Spindleheads of the mentioned type are already known, in which the spindle driving motor is structurally integrated with the headstock. This means that the spindlehead becomes very heavy and that the guideways for the spindlehead are always loaded by the weight of the driving motor. Furthermore, in particular in the case of exchangeable spindleheads, each spindlehead must have its own driving motor, which is very expensive and makes the exchange operation more difficult.
It is the purpose of the present invention to produce a spindlehead of the above-mentioned type, in which the afore-mentioned disadvantages are avoided, namely in which the driving motor does not load the spindlehead guideways and which is exchangeable, without that the spindle driving motor must always also be exchanged.
This purpose is inventively attained in such a manner that the spindle driving motor is supported movably in direction of the feed movement of the headstock on separate guideways and is coupled with the headstock through a releasable carrier connection.
During operation the spindlehead behaves like an integrated unit of headstock and spindle driving motor, namely the spindle driving motor partakes in the movements of the headstock, so that the driving connection between motor and spindle is without any problems.
However, the spindle driving motor does thereby not load the highly exact spindle guideways, but same can be supported on separate, less exact guideways.
In exchanging the headstock, the carrier connection is released and the headstock alone is exchanged for another one. In the case of a spindlehead with a feed movement which is directed perpendicularly with respect to the direction of the spindle axis it is provided inventively, that the spindle driving motor is arranged behind the headstock in spindle axis direction. Thus the spindle driving motor moves on guideways which are arranged parallel with respect to the headstock guideways. This arrangements has the advantage, that the spindle driving motor does not limit the movement of the headstock.
The carrier connection can be constructed very simply. According to a characteristic of the invention, it is provided that the carrier connection is constructed as a jointed connection, which transmits forces only in carrying direction. Therewith, an exact alignment of both coupled parts is not necessary, small position inexactnesses, for example of the driving motor, are balanced out and do not result in reciprocal bracing.
A further development of the invention provides that the carrier connection consists of a finger which is arranged on the spindle driving motor -- or a motor carrier --, which finger engages a fork piece which is arranged on the headstock or vice versa, and that in the two legs of the fork piece there are arranged setscrews having an approximately semispherical dome or free end, which setscrews can each be screwed against the finger.
In the case of a spindlehead with a vertical feed movement, it is possible according to a characteristic of the invention to provide a counterbalance weight for the spindle driving motor. The counterbalance weight, however, can also be designed for the entire unit which consists of the headstock and the spindle driving motor.
One exemplary embodiment of the invention is illustrated in the drawing and will be described more in detail hereinafter.